Clutch mechanism.



J. G. MAGPHERSON.

CLUTCH MECHANISM.

APPLICATION FILED JUNE 17, 1914.

mechanism,

' able members eludes the gradual exact description of clutch member,

UNITED STATES PATENT OFFICE.

501m e. M rHERSQN. or rmnann rnm, PENNSYLVANIA, Assmnon o aosnrn c.

BAIBD, WASHINGTON,

rnnusvnvama CLUTCH MECHANISM.

To all whom it may concern:

Be it known that I, JOHN G. MACPHER- soN, a citizen of the United States, residing in the'city of Philadelphia, county of Philadelphia, State of Pennsylvania, have invented certain new and useful Improvements in Clutch Mechanism; and I do hereby declare the following to be a full, clear, and the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to clutch operating and more particularly to mechanism for controlling clutches of power driven vehicles, such as automobiles, locomotives and the like, employing comparatively -large powers, in which therelatively movof the clutch are normally moved into engagement with each other to effect the coupling between the driving and driven shafts, by means of a spring or equivalent yielding power applying device. In such clutch operating mechanism as heretofore employed, it has been customary to provide the movable member of the clutch with lever mechanismto retract the same from engagement with the cooperating which lever mechanism was arranged to be operated either byfhand or or in the alternative, by some mechanical fluid pressure operated or electrically operated apparatus. by means of which the movable member of the clutch was retracted and held in such retracted position until the power was released, to permit the spring to cause the clutch members to again engage each other. With clutches designed to transmit relatively large powers from the driving to the driven shaft. the heavy spring emplayed to pply the clutch practically preengagement of the clutch members. but forces the clutch parts together violently, thereby endangering not only the clutch mechanism itself, but transmitting the shocks and strains to the entire driving system including the prime mover. It has been found practically impossible to apply hand or foot power devices to effect the release and engagement of such clutch members to avoid the difficulties enumerated, and even the application of power-operated means to effect the operation of the clutch has proved ineffective to produce a gradual and ni o m pplication of orc bet e n Specification of Letters Patent. Application filed June 17, 1914. Serial No. 845,67.

Patented Mar. 9, 1915.,

the'engaging clutch members, which is so essential to the preservation of the apparatus and the smooth, uniform operation of the vehicle. D

- The purpose of the present invention is to provide means in connection with the spring applied clutch to produce a steady, even, uniform engaging movement of the clutch members, which will prevent any sudden shocks, jars' or strains on the mechanism,

- and which will also admit of an instantaneous release of the clutch. To these ends, the invention contemplates the association with a clutch in which the movable member is normally spring-pressed into engagement with its cooperating member, of a second and stronger spring opposing the action of the first spring, means for overcoming and n'ullifying, preferably gradually, the effect of ,the second spring, so that the clutch-applying spring will gradually take up its action as the effect of the Opposing spring is overcome and the two members of the clutch will be brought into operative engagement without shocks or jars and without imposing any sudden or undue strains on any part of the driving mechanism. The preferred means for overcoming or nullifying the action of the second or heavier spring takes the form of a'fiuid pressure actuated device under direct control of a simple valve which will applv and release fluid pressure to and from said mechanism, thereby permitting the clutch to be gradually and evenly applied, but to be instantaneously released. The accompanying drawing is a diagram matic view, partly in section of a typical friction clutch having the invention applied thereto. J

. Referring to the drawing, 1 indicates the drlving shaft to which is secured one clutch member 3 which takes the form of a fly wheel having into ender compression between said block and an the clutch member-4 in either direction may be controlled in the usual manner.

' As thus far described, the apparatus does not differ essentially from the usual form of spring-operated friction clutches commonly employed on automobiles and like vehicles,-

and in the normal operation thereof, the spring 6 holds the clutch members in cooperating engagement and thereby couples the driving and driven shafts for the transmission of power from the prime mover to the driving axle or axles of the vehicle.

Pivotally secured to the free end of shipper lever 7 is a rod 10, to the forward end of which is secured a piston 12 operating in a cylinder 13, the forward end of which is provided with inlet and exhaust pipes 17 and 18 respectively, which in turn connect with any appropriate form of control valve 19, which latter is provided with an exhaust port which opens to the atmosphere by way of pipe 20. Said valve 19 is in communication with a source of fluid pressure, preferably air, contained in a tank 22, by means of pipe 21. Rod 10 is slidably mounted in an abutment block 16 which is bolted to some stationary part of the machine frame, and surrounding the block and confined unadjustable collar 15 is a helical spring 14,

which is so adjusted as to normally overcome or nullify the effect of the clutch operating spring 6 and thereby hold clutch member 4 out of engagement with cooperating clutch member 3.

The operation of the device as thus described is as follows. When the supply of fluid pressure is cut off from cylinder 13 and the latter is open to the air by way of valve 19, the predominating power of helical spring 14 overcomes the effect of clutch .applying spring 6 and causes the shipper lever '7 to move clutch' member 4 out of engagement with its coiiperating clutch member 3 so that the driving and driven shafts are disconnected. \Vhen it is desired to couple the driving and driven shafts, valve 19 is operated to gradually admit ,air from thesupply tank 22 to the cylinder 13. thereby advancing the piston 12 gradually and compressing spring 14 between the station-- ary abutment 16 and collar 15 by the advancement of piston rod 10, which rocks shipper lever 7 and permits the spring 6 to force movable clutch member 4 into engagement with clutch member 3 with a steady, uniform and gradually increasing pressure. When thepiston 12 reaches the limit of its power stroke, the clutch members will be in firm engagement due to the full pressure effect of the spring 6, which effect. however, has been gradually and uniformly applied so that no sudden shock or strainis put upon the clutch members or any of the parts connected therewith. When it is desired to re features of construction and operation.

"of the second spring.

' bers into engagement,

lease the clutch, the valve 19 is operated by its handle to shut off the power supplied by the compressed air tank 22 and to open up communication between the air release pipe 18 and the exhaust pipe 20. This relieves the tension of the air in the cylinder 13 and permits the spring 14 to force the piston rcarwardly and also to rock shipper lever? in a direction to retract clutch member 4 from engagement with clutch member 3, the entire operation being practically instantaneous so that an exceedingly quick release of the clutch is effected.

By adjusting the relative tensions of the springs 6 and 14, the power required to permit the application of the clutch may be nicely controlled and unnecessary expenditure of compressed air avoided. It is necessary only that the power of spring 14 be suflicient to overcome that of spring 6 so that the latter is ineffective to force the clutch members into engagement untilthe effect of said spring 14 has been practically nullified, and by gradually overcoming or counteracting the effect of spring 14, a gradual and uniform application of the pressure of spring 6 to the movable member 4 of the clutch is possible of realization bv the proper manipulation of the handle of valve 19.

The apparatus as illustrated and described is to be regarded as merely exemplary of the invention, and it is to be understood that the invention is capable of many modifications without departing-from the essential though a typical form of friction clutch is illustrated, it is apparent that theinvention is eouallv applicable to any of the usual forms of clutches as now employed. Likewise the particular type of mechanism for overcoming' the effective action of the counterbalancing spring 14 maybe varied to suit conditions. as also maybe particularmeans for connecting the two springs 6 and 14.

Whatl claim is:

1. The combination of a relatively movable engaging members, a spring normally tending to force said members into engagement, a second and stronger spring opposing the action of the first spring, and means for nullifying the effect 2. The combination of a clutch having relatively movable engaging members, a

clutch having spring normally tending to force said mema second and stronger spring opposing the spring. and means for gradually nullifying the effect of the second spring.

3. The combination of a clutch having relaction of the first.

atively movable engaging members. a spring normally tending to force said members into engagement, a second and stronger 5 ring opposing the action of the first sp fluid pressure actuated means for nullifying the effect of the second spring.

4. The combination of a clutch having relatively movable engaging members, a spring normally tending to force said members into engagement, lever mechanism for moving one clutch member in opposition to said spring, a second and stronger spring connected with said lever mechanism opposing the action of the first spring, and means for nullifying the efiect of the second spring. 5. The combination of a clutch having relatively movable engaging members, a spring normally tending to force said members into engagement, a shipper lever for retracting the movable clutch member, a fluid pressure cylinder, a piston therein, a connecting rod between said piston and said shipper lever, a second and stronger spring interposed between said rod and a fixed abutment normally opposing the action of said first spring, a source oi fluid pressure, and connections including a supply and relief Valve between said source and said cylinder.

In testimony whereof I atlix my slgnature, in presence of two witnesses.

JOHN G. MACPHERSON. Witnesses:

' ARTHUR L. BRYANT,

CHAsJ. ONEILL. 

